Looking into the Future - Australian Population Projections (Feature Article)

Special Article - Looking into the Future - Australian Population Projections (Mar, 2000)

This article was published in Australian Demographic Statistics, March Quarter 2000 (ABS Cat. no. 3101.0)

AUSTRALIA

Population projections spanning the period from 1999 to 2101 for Australia and 2051 for the States and Territories and capital cities/balance of States were released on 17 August 2000. The projections use a combination of assumptions of future fertility and mortality rates and varying levels of migration to project the possible size, structure and distribution of Australia's population into the next century.

Three main series have been published. Series I assumes a total fertility rate (TFR) of 1.75 babies per woman and net overseas migration of 110,000 per year. Series II assumes TFR falling to 1.6 in 2008 and then remaining constant and net overseas migration of 90,000, while Series III assumes a TFR of 1.6 from 2008 and net overseas migration of 70,000. All series assume that life expectancy at birth will increase to 83.3 years for males and 86.6 years for females in 2051, then remaining constant until 2101. Net overseas migration levels are phased in and remain constant from 2002.

In 1998 the TFR was 1.76 babies per woman and life expectancy at birth was 75.9 for males and 81.5 for females. Net overseas migration for 1998-99 was 85,100 (revised) but the average level for the last 20 years was 95,000.

Population size and growth

Australia's population is projected to grow from 19 million in 1999 to between 24.1 and 28.2 million in 2051, and to between 22.6 and 31.9 million in 2101. The contribution of natural increase (the excess of births over deaths) to this growth would decline throughout the projection period, becoming negative between 2033 and 2046. After this time, all growth would result from net overseas migration.

Throughout the 1990s, Australia's annual population growth rate has consistently exceeded 1%. While growth rates of this magnitude are projected to continue for about the next 10 years, these would decline throughout the remainder of the projection period to between 0.4 and -0.6% by 2051.

PROJECTED POPULATION, Australia

Population ageingOf all the changes that are projected to occur in Australia's population, ageing is the most dramatic, resulting in major changes to the age structure of the population. The projections show that the ageing of Australia's population, which is already evident, will continue. This is the inevitable result of fertility remaining at low levels over a long period associated with increasing life expectancy. As growth slows, the population ages progressively with the median age of 35 years in 1999 increasing to 40-42 years in 2021 and 44-47 years in 2051.

Older peopleThe population aged 65 years and over is projected to increase rapidly throughout the first half of the period both in terms of numbers and as a proportion of the total population, from 2.3 million in 1999 to about 4.2 million in 2021 and between 6.4 and 6.8 million in 2051. By 2101, the size of this group would range from 6.2 to 7.9 million. As a proportion of the population, this represents increases from 12% in 1999 to 18-19% in 2021, 24-27% in 2051 and 25-28% in 2101.

The growth rate of this group increases rapidly in the early years of the projection, peaking in 2012 at just over 4%, when the large cohort born in 1947, part of the post World War II 'baby boom', turns 65. Growth continues at about 3% each year for the following 15 years as successive cohorts of the baby boom move into the age group. The growth rate then declines, reaching 0.4-0.7% in 2051 and -0.1-0.2% in 2101.

The very old populationIn 1999 the 85 years and over age group was relatively small, at 241,000 (1.3% of the total population). This group is projected to experience the highest growth of all age groups within the population, with peaks in 2006 (6%) and 2032 (7%). These peaks represent the cohorts born in 1921 and 1947, parts of the post World War I and World War II baby booms, respectively. Under all three series, this group is projected to more than double in size within 25 years, and reach approximately 1.3 million in 2051 and 1.3-1.6 million in 2101. Growth of this magnitude has important implications for the provision of health services and appropriate housing, given that non-private dwellings are the most common form of housing for people in this age group.

The other noticeable change in this age group is the decreasing proportion of women, which is associated with the increase in life expectancy of men and the narrowing gap in life expectancy between men and women. In 1999, 69% of the population aged 85 years and over were women. In all series this proportion is projected to fall to 63% in 2021, 59% in 2051 and 57% in 2101.

Population aged 15-64 yearsThe population aged 15-64 years, which encompasses much of the working-age population, made up 67% of Australia's population in 1999. This proportion would increase over the first ten years of the projection under all the main series to reach 68% in 2008. It would then decline to 65% in 2021, 59-60% in 2051 and 58-59% in 2101.

PROPORTION OF POPULATION IN AGE GROUPS, SERIES II

STATES AND TERRITORIES

Series II shows the population increasing over the next 50 years in all States and Territories, except Tasmania and South Australia. Between 1999 and 2051, the population of the Northern Territory is projected to increase by 92%, Queensland by 74% and Western Australia by 63%, well above the growth projected for Australia (34%). One outcome of this is that the geographic distribution of Australia's population is projected to be noticeably different in 50 years time.

Changing State shareNew South Wales is projected to remain the most populous State in Australia, although New South Wales' share of Australia's population is expected to fall slightly from 34% in 1999 to 32% in 2051. In Series II, Victoria would be replaced by Queensland as the second most populous State in 2038 with Victoria's share of Australia's population decreasing from 25% to 22% over the next 50 years and Queensland's share increasing from 19% to 24% over the same period.

In Series II, Western Australia increases its share of Australia's population from 10% in 1999 to 12% in 2051 while South Australia's share falls from 8% to 6% over the same period. Similarly, Tasmania's share is set to decline in this series from 2.5% in 1999 to 1.3% in 2051. In contrast, the Northern Territory, which in 2046 is projected to overtake Tasmania in terms of population size, is set to increase its share of Australia's population from 1.0% to 1.5%. Series II projects that the Australian Capital Territory will decline in share from 1.6% to 1.5% over the next 50 years.

CHANGES IN ORDER OF POPULATION SIZE

Series I

Series II

Series III

Change in order

year

year

year

States and Territories

Queensland overtakes Victoria

2026

2038

(a)

Australian Capital Territory overtakes Tasmania

2041

2041

2047

Northern Territory overtakes Australian Capital Territory

2048

(a)

2048

Northern Territory overtakes Tasmania

2044

2046

2047

Capital cities/balances of States

Darwin overtakes Hobart

2038

2040

2045

(a) Event does not occur during the 1999-2051 projection period.

Increasing capital city growth and shareIn Series II, all of the capital cities will experience larger percentage growth than their respective balances, resulting in the further concentration of Australia's population within the capital cities. In 1999, 64% of Australians lived in capital cities, but by 2051, this could increase to 68%.

In this series Sydney and Melbourne remain the two most populous cities in Australia at 5.9 and 4.4 million, respectively in 2051, followed by Brisbane (2.9 million), Perth (2.2 million), Adelaide (1.1 million), the Australian Capital Territory (371,700), Darwin (192,200) and Hobart (146,200). In Series II Darwin overtakes Hobart, in terms of population size, in 2040.

Impact of international migrationNet overseas migration can have a large impact on population size over time, although its impact varies considerably across the States and Territories. The analysis below looks at the difference in the size of the 2051 population produced by use of the high net overseas migration assumption and the assumption that provides for zero gains. For the purpose of this analysis, the fertility and net interstate migration assumptions are held constant so that the impact of net overseas migration can be isolated. In reality it is unlikely that this would be the case.

Currently, New South Wales receives the largest amount of net overseas migration of all the States and Territories. In the last three years (1996-97 to 1998-99) New South Wales received 43% of Australia's net overseas migration, followed by Victoria (23%), Queensland (16%), Western Australia (14%), South Australia (4%), the Northern Territory (0.6%), the Australian Capital Territory (0.3%) and Tasmania (0.1%).

The three largest States are projected to continue to make the largest population gains from net overseas migration over the next 50 years. For New South Wales, the high net overseas migration assumption adds 3.3-3.4 million more people to the 2051 population than if there had been zero net overseas migration during the projection period, a difference of 36-38%. Similarly, if there were no net overseas migration over the next 50 years, Victoria's population in 2051 would have 1.8-1.9 million fewer people, 27-33% fewer people than if the high assumption had been used. Queensland could also expect to gain 1.3 million people over the next 50 years through net overseas migration under the same scenario, 18-22% more than if there were no gains from net overseas migration.

While the net overseas migration gains projected for South Australia are smaller in number, they could increase the size of the population by 17-20% by 2051. South Australia could gain between 272,200 and 285,900 people from net overseas migration over the next 50 years. Western Australia is projected to make more substantial gains during the projection period, with the high net overseas migration assumption adding 1.1 million to the population by 2051, 32-35% more than if there were zero net overseas migration.

Net overseas migration has a much smaller impact on the population size of the smaller States and Territories. The Northern Territory is projected to add between 61,700 and 69,300 to its population by 2051 under the high assumption, 14-22% more than if there were no net overseas migration gains. For the Australian Capital Territory, the high assumption adds between 33,600 and 38,200 to the 2051 population, 8-13% more than if there had been no net overseas migration. Tasmania is projected to make the smallest gains from net overseas migration. Under the high assumption, between 17,600 and 20,100 people will be added to the population by 2051, 5-7% more than if there were no gains.

ADDITIONAL INFORMATIONFor further information on population projections see Population Projections, Australia, 1999-2101 (Cat. no. 3222.0) released on 17 August 2000.